Mariah Carey lived in "denial and isolation" when she was diagnosed with bipolar disorder.
The pop diva was first diagnosed back in 2001, after being hospitalised for both a physical and mental breakdown, but admitted she didn't want to "believe it" but revealed she sought treatment and is on medication.
In a candid interview with PEOPLE Magazine, Mariah said: "I didn't want to believe it.
"Until recently, I lived in denial and isolation and in constant fear someone would expose me.
"It was too heavy, a burden to carry and I simply couldn't do that anymore. I sought and received treatment, I put positive people around me and I got back to doing what I love - writing songs and making music.
"I'm actually taking medication that seems to be pretty good. It's not making me feel too tired or sluggish or anything like that.
"Finding the proper balance is what is most important."
The 'We Belong Together' hitmaker went on to say she originally thought she had a "severe sleep disorder".
The music icon- who is working on an album which is expected to land this year - said: "For a long time I thought I had a severe sleep disorder.
"But it wasn't normal insomnia and I wasn't lying awake counting sheep. I was working and working and working... I was irritable and in constant fear of letting people down.
"It turns out that I was experiencing a form of mania. Eventually I would just hit a wall.
"I guess my depressive episodes were characterised by having very low energy. I would feel so lonely and sad - even guilty that I wasn't doing what I needed to be doing for my career."
The pop superstar has won five Grammy Awards, 19 World Music Awards, 10 American Music Awards and 14 Billboard Music Awards.